Heat Stress And Its Amelioration In Commercial Poultry Farms

1 2* 3 2 Mahesh Kajagar , Yallappa M. Somagond Sachin S.P V. R. Upadhyay and Pooja Devi 2 1 MVSc (Animal nutrition), KVASU, Kerala 2 Research Scholar, Animal Physiology Division, ICAR-NDRI, Karnal-132001 3 MVSc (LPM), KVASU, Kerala 2* Corresponding author Email –somagondyallappa@gmail.com

Introduction

Poultry farming is a domestication of different type of birds and marketing of meat, eggs and feathers of different types of birds. Chicken is the commonest and most commonly raised poultry. Approximately 5 million chicken (meat and chicken eggs) are raised annually as a source of food. The chickens that are grown for eggs are called layer chicken. Chickens are grown for their meat production are broiler chickens. Chicken are mostly affected by heat stress during summer season. In warm countries, steps must be taken to continue maintained production and avoid poor heat-related flock efficiency, though not all mitigation steps can be economically justified in areas where temperature rises are only occasional.

Effects of heat stress in commercial poultry farm 1 Effects of heat stress on feed consumption

Feed intake - there is decrease of 1.5 g of feed intake for every °C increase in of temperature between 26 and 32°C and decrease of 4.2 g for every °C increase in temperature between 32 and 36°C. Energy - In light poultry strains, the regulation of feed intake mainly based on the energy content of the diet, this happens a s l o n g a s t h e a m b i e n t temperature does not exceed much over 30°C. 1`Proteins - Protein requirements remain same even at high temperatures. Nitrogen retention is highest between 16 and 22°C and decreases on both sides of these two values. Due to the reduction in feed intake and lower nitrogen in hot climates, so it is necessary to increase dietary protein concentration during heat stress conditions.

2 Effects of heat on water

consumption – increase in ambient temperature results in increase in water consumption. It increase in water intake by 2x when the temperature rises from 21 to 32°C and 3x when it goes from 21 to 37°C. The Water/Feed ratio increases rapidly as the temperature increases, reaching values close to eight at around 37°C. 3 Effects of heat on growth - In broilers, there is the decrease in daily weight gain due to decrease in bird metabolism and intestinal nutrient absorption.

4 Effects of heat on viability -

Mortality from heat shock is mainly due to heart failure related with nervous disorders resulting from alkalosis and chronic hypoxia.

5 Effects of heat on egg laying –

increase in temperature affects the quality and quantity of egg production. This impact is mainly due to decrease in energy intake and various nutrients, disturbance

in homeostasis and reduction of blood flow in internal organs, including the ovary because of increased blood flow to periphery. The resulting drop in egg production is more affected when the temperature along with an increase in relative humidity.

Decrease in egg weight comes with greater shell breakability due to alkalosis and calcium leakage.

T h e r a p e u t i c m e a s u r e s t o ameliorate effect of heat stress 1 Correcting the acid-base balance

a) Sodium bicarbonate (NaHCO3) is administered in drinking water at a concentration of 0.5% or incorporated into the feed at a concentration of 4 kg/ton. b) Ammonium chloride (NH4Cl) is administered in drinking water at a concentration of 0.3 to 0.5%, with a risk of acidosis beyond 0.6%. The combination of

NaHCO3 and NH4Cl at suggested doses gives better results than by administering them separately. c) Sodium chloride (NaCl) at a dose of 3 to 5 g/l does not generate alkalosis, but increases the ingestion of water as long as its temperature is relatively low. d) Potassium chloride (KCl) at a concentration of 0.1 to 0.2% may also be used.

2 E n e r g e t i c s u b s t a n c e s -

Carbohydrates recompense for energy losses and increase